Fallen
by SirienneHolmes
Summary: M for blood and gore. If you have a weak stomach, be advised. I watched you let yourself die, and now it's too late to save you this time. Sherlock meets his greatest enemy, face to face. Could it just be...himself?
1. The Impossible

**Chapter 1: The Impossible**

Doctor John Watson had never been asked to believe in amazing or impossible things. He had been in the war. He'd seen impossible cruelty and amazing heroics. He was a friend of Sherlock Holmes. That alone was impossible and amazing wrapped into one.

Sherlock had never asked John to believe the things he accepted as fact, but then again, John rarely questioned Sherlock. He simply followed the amazing genius on faith. Now, Sherlock was asking (one might say "begging," if Sherlock Holmes could beg) John to believe something that was downright mad.

John didn't want to believe Sherlock was mad. He felt that madness meant something entirely different to the consulting detective, regardless of what Sally Donovan thought about it.

"I tell you," Sherlock was pacing back and forth, occasionally brushing against the mantle in his haste. He was anxious and excited at the same time, his eyes and hair wild. "This man _was_ me! But, he wasn't me! Arrrgh!" Sherlock growled and threw himself into his armchair. "I swear, John! He was _here_ last night!"

"You mean while I was on my date with Sarah?" John asked, trying to remain calm. The last thing he wanted to do was give the obviously stressed detective the impression that he didn't believe him.

Which wouldn't have been true. John _did_ believe him, even though the story seemed farfetched. He was merely testing Sherlock's boundaries.

"Yes," Sherlock snapped, his teeth clicking together noisily. "He sat right where I'm sitting. Like this, mostly," Sherlock leaned back in his chair and steepled his fingers. It was his thinking pose. Then, the demonstration over, he snapped forward with the swiftness of an agitated snake. "He had this demonic grin."

"Well, I believe you," John said with a sigh.

Sherlock's eyes brightened. "Good. You know I never lie to you."

"Once, you did."

"Ahh. Baskerville. But it was for a _case_, John. I never lie without good reason."

"I know." John folded the paper and put it aside, leaning forward towards the consulting detective, who moved back in the chair an inch. "What I don't understand is why you're so worried about him. I mean, what could he possibly do?"

Sherlock's hands trembled on his knees and his eyes widened, his lips parting just slightly. He swallowed, and John thought he detected fear. Fear? Since when was Sherlock afraid? Not since Baskerville had John seen his friend in such a nervous state! "Everything, John," he whispered between anxious swallowing, "there's no one who can ruin my name better than someone who looks just like me."


	2. Under Lock and Key

**Chapter 2: Under Lock and Key**

John was out for the evening on a boring date with boring Sarah. Sherlock was in the process of making tea, something he rarely did for himself, getting ready to settle down to the chemistry textbook he had just ordered. Then, he heard the door open, heard someone step inside. It couldn't be John. Maybe it was Mrs. Hudson. He heard the other body collide with the leather armchair—_his_ chair—and sigh. So, it was a man, then, but not John. Then who…?

It was then that the body chose to have a voice. And it was a voice that sent chills down Sherlock's spine.

"It's _amazing_ what keys will open what! Imagine that! I don't think I had such an easy time back home!"

Sherlock's brain tried to wrap around the data he'd just processed, but his mind seemed to be babbling. _That's my voice! __**My voice**__! A bit hysterical—there's a high pitch when he ends his sentences, like Moriarty almost. But…that's impossible! __**Mycroft**__ doesn't sound that much like me, and we're __**related**__!_ He ran into the living room, his riding crop at the ready (thank God he'd been pulverizing a dead chicken with it earlier, or he wouldn't have had it on him!), but was very shocked to see what he saw.

It was a splitting image of himself, sitting languidly in his chair. But there was something…off…about this other Sherlock. Strands of the dark hair were tinged red at the edges, and his white shirt seemed to be stained with blood at the cuffs. Though he was tall and certainly thin, he seemed to be heavier. Sherlock estimated himself to be about 12 stone; this mirror image man appeared to be about 14 stone. The eyes were closed, but they opened now, and Sherlock was horrified to see that the irises were partially tinted red.

"Well, well, if it isn't Sherlock Holmes!" The other Sherlock laughed and stretched out his hand. "Pleased to meet you! I'm Lockmes, although you can call me 'Lock.' People do." As he smiled, Sherlock noticed that his teeth were also tinted red, which made him even less inclined to take the outstretched hand. Lockmes retracted his hand. "Ahh, I see. You're less social than I am. Of course, I'm not very social, either," he leaned back again. "We could be twins! Don't you think?"

"No." Sherlock narrowed his eyes. "You're covered in blood."

"Brilliant deduction, but I was hoping for something a bit more clever." Lockmes smirked.

Sherlock ran his eyes over the figure before him. Besides the blood on his shirt and the discarded coat and scarf that lay at the other man's feet, blood had soaked into the edges of his black dress shoes and there were spatters on his wrists and cheeks. His canines were sharp, sharper than any human's. Unless…

"Cannibal," Sherlock breathed, the word sending a wave of illness through him. There were very few things that could disgust Sherlock Holmes, and cannibalism was one of them. Of course, cannibals only existed on the telly and in nightmares.

…right?

Lockmes smiled widely and clapped his hands. "Yes! Yes! Brilliant! You're absolutely right! You're good, you know," he settled again, and walked his fingers down his stomach. "You may have noticed I've put on a few pounds. Well, let's just say, human flesh isn't necessarily low calorie." His eyes burrowed into Sherlock's with such intensity that Sherlock almost felt the need to look away. He didn't want to know what kind of sick man he was dealing with. And yet, he did.

"Why are you like this?" he asked.

"Sit, Sherly. You might as well, it's a long story." Lockmes gestured to John's chair. Sherlock sat warily and watched his twin. Lockmes adjusted his suit and then began to narrate in his deep, cool, but slightly hysteric voice. "Not long ago, I was just like you. I was content with solving crimes and having my name in the papers. Then, I got bored." He blinked, looking at Sherlock suddenly when before he'd been looking down. His eyes widened and his voice rose an octave. "I got so bored, not only of the petty crime in UnderLondon (that's where I live, by the way), but of, well…food." He snapped his teeth together. "Tea and biscuits and pasta and Chinese…it's all so _boring_, really. So, I started to eat raw meat. Oh, it was only cows and that sort of thing at first, but I was more surprised when my body didn't reject it! In fact, I felt stronger than ever! Animal blood became boring, too, so I started looking for human remains. How I frightened little Molly at the mortuary! They dragged her away, to an insane asylum! Lucky they believed me!" He chuckled. "They should've believed her, but such is the dull life of UnderLondon." Sherlock narrowed his eyes and bared his teeth. He felt protective of the people he knew, Molly being one of them, and, though it wasn't his Molly being threatened, it still hit him hard. "Ah well. Soon, corpses became too dull as well, and I had to look for more…fresh…prey. Of course, my brother Myhol had found out about Molly's 'episode' and confronted me." He sighed, almost as if it pained him. "It made me so very sad to have to kill my poor brother. But he was simply…in the way. And such lovely human remains could _not_ be allowed to go to waste…" Lockmes licked his lips hungrily, but Sherlock felt he was going to be ill. "So, yes, I ate his insides. I hadn't a taste for skin, then, so I ate his heart and stomach and all that, lapping up his blood. Myhol was delicious." He patted his belly, then. "Well, after that, you know, I was out of control. Poor John Nostaw, he didn't know I'd gone mad until one night when he found me eating sheep entrails! Oh, when I'm too lazy to kill, they'll satisfy my hunger. Anyway, he begged me to let him help! The poor devil! He wanted to be my friend, even though I told him how tasty he looked!"

"You can't mean you _ate_ your John!" Sherlock cried, appalled.

"No, no, relax!" Lockmes cackled at Sherlock's shock. "No, I haven't. Not yet, anyway." Sherlock turned green and swallowed thickly, making himself small in John's chair. "Once he stops being of any use to me, _then_ I'll eat him. But, you understand, I'll do it with such _love_,"

"Demon!" Sherlock snarled. "You _can't_ love!"

"And that's the idea of us!" Lockmes gestured towards himself and then out to Sherlock, which shut up the other man quite quickly. "They said we were incapable of having friends! Of falling in love! They said we were capable of so much more! I only proved them right, dear Sherly. Now it's your turn." He winked and held out his hand again. "Join me. Join me, Sherly, and we'll become London's terror!" And he cackled like a madman.

"_Never_." Sherlock hissed. "Never will I be like you! Never."

"Hmm," Lockmes was rubbing his stomach. "You might change your mind, once I'm through with you. In fact," he chuckled, "you may not have a choice. He was delicious, by the way."

"Who?" Sherlock fought to keep the anxiety from his voice. It seemed the only man he was afraid of was himself.

"Oh, don't worry, your little John is safe." Lockmes waved off Sherlock's worry. "No, no, I didn't kill. I devoured a newly-dead man and threw the bones in the Thames. It was no one special, just a homeless beggar. I doubt the stupid police of Scotland Yard would lift a finger about it. Just like the UnderYardies."

Sherlock got up. "I don't have to hear this. Get out."

Lockmes stood up and put a hand on Sherlock's shoulder. "You poor baby," he soothed, "you think you can escape, just by ignoring me? Sherlock, I'm _here_. And I'm here to stay. I don't mean to ruin your life, but I'm going to get hungry again sooner or later. And honey, already-dead bodies are just _not_ going to cut it! Although, I don't know how they fatten themselves!" Lockmes seemed disappointed, which prompted Sherlock to turn around. He was eye-to-eye with this distorted image of himself. "I'm going to be full for a long time! Longer if I show you…" He passed by Sherlock and headed for the fridge. Sherlock watched as Lockmes took out a bag of sheep entrails he had been keeping for an experiment. Then, he tried very hard not to be sick on the kitchen floor as Lockmes ate the sheep entrails in front of him.

"Here!" Lockmes said cheerfully, holding out a handful of the nasty, bloody things. "Try some!"

Sherlock shook his head. "I'm not hungry."

"Suit yourself!" Lockmes sang, before downing the rest of the entrails and delicately licking his fingers of the blood. "Ahh, now I'm _really_ full! Well, Sherly, be ever so careful what you tell your Yardies! We're alike, you and I! They'll be on to you like a hawk on a rabbit!" Lockmes put on his coat and tied his scarf about his neck. "Sorry, dear, but I've got to get back to my John." He opened the window and crouched on the ledge. "Tootles!" And with a familiar smirk, he jumped out, only to be swallowed up by the London night.

Sherlock pinched himself thrice before closing the window and then whipped his thigh with the riding crop twice for good measure. Nope, his wounds stung. He was awake, unfortunately. Sherlock bent over the sink and was sick until he was only retching. Then, he promptly went into his bedroom and locked the door until he heard John enter the flat.

Lockmes. Lock. The demon consulting detective of UnderLondon.

How in hell did he get here?


End file.
